118.USMI

Question 1

normal control of continence in female dogs

Answer 1

1. tone of urethral smooth muscle (“internal sphincter”)2. tone of urethral striated muscle (“external sphincter”)3. natural elasticity of connective tissue of urethra4. urethral length and diameter5. bladder neck position6. degree of engorgement of suburothelial venous plexus (may be increased in spay dogs)

Question 2

urethra, bladder, gonadectomy status and breed associated with USMI

Answer 2

–poor urethral tone—shortened urethral length–pelvic bladder (changes in transference of P)–large giant breed dogs (generally obese)–SPAYED (timing does not matter)–may have concurrent vaginovestibular abN (does not cause USMI though)

Question 3

incidence of acquired USMI in spayed female dog population

Answer 3

18-20% female spayed are 8x more likely to get than intact3-5 years after OHE

Question 4

T/Ffemales have a higher collagen to muscle ratio

Answer 4

TRUEneutering can affect the balance bc gonadectomized dogs have more collagen and less muscle than intact, but females have less than malesovariectomy has NO effect on collagen types or smooth muscle actin

Question 5

2011 deBleser risk factors for USMI

Answer 5

increasing animal agebreed (old english sheepdog, root, irish setter, dobie)obesity (30% USMI in dogs > 30 kg)spayed—but TIMING of spay does NOT influence incidenceOE vs OHE (no evidence that it matters) tail docking?

Question 6

medical mgmt of USMI

Answer 6

–sympathomimetic: PPA (phenypropanolamine): alpha adrenergic–increase urethral tone; most popular tx 85% success–parasympatholytic: reduces intravesicular pressure–hormone therapy: Diethylstillbestrol (DES) synergistic with PPA; response to DES alone may decrease due to desensitization of estrogen receptors–GnRH analogues: 50% continent 70-750 days unknown MOA but thought to decr circulating LH/FSH

Question 7

T/F~ 50% of juvenile bitches become continent after their first estrus

Answer 7

TRUE

Question 8

surgical options for USMI

Answer 8

—colposuspension—urethropexy, vas deferentopexy, prostatopexy—bovine collagen cystoscopic injections/urethral resistence—hydraulic artificial urethral sphincter—Transobturator vaginal tape —bladder neck reconstruction

Question 9

success of bovine intraurethral collagen bulking agents

Answer 9

70% continent ~ 17 mo40% recurrence ~ 8 momay need multiple injections

Question 10

success of colposuspension or urethropexy

Answer 10

colposuspension 50% at 2 mo vs 14% at 1 yrurethropexy 70% at 1 yr 60% 36 mo and 30% > 36 moon average 50% success, may need rx or additional procedures

Question 11

anatomic landmarks of colposuspension

Answer 11

vagina to prepubic tendon/thru rectus abdominus muscle/fasciaavoid external pudendal vessels2 sutures on each side

Question 12

HAUS–hydraulic artificial urethral sphincter

Answer 12

silicone cuff and tubingpassed around proximal urethra, exit caudal ab and connected to huber portcuff inflation is delayed 6 weeksinflated 25% incrementsUS guided cystocentesis recommended to RO incontinence from infection prior to inflationinitial success 75% in four dogs at 2 yrs

Question 13

prognosis of USMI in males

Answer 13

–don’t respond well to medical mgmt–sx less successfulsurgery options: –vasopexy, prostatopexy–bladder neck reconstruction–HAUS–collagen injections–transpelvic sling

Question 14

complications following surgery for incontinence

Answer 14

—continued incontinence–dysuria—inability to urinate/urinary obstruction–stranguria–infection